In this revised renewal application, we have continued to direct our attention to the lipid storage disease deposits of Gaucher's and Krabbe's diseases by considering their structure as determined by electron microscopy and x-ray diffraction. In addition, we now plan a more extensive biochemical analysis of the various components of the deposits, as well as a characterization of the sphingolipid enzymes that are defective in these diseases. Finally, we plan to investigate the conditions necessary for sphingolipid deposit catabolism with the intension of providing a basis for therapy, either directed toward preventing deposits from forming or enabling deposit breakdown in patients with an already established sphingolipid storage state.